Railway traffic controlling apparatus



May 5, 1936.

R. A. MOCANN Er AL RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Nov. 15, 1934- IN VENT 0R6 Ronald A.M.Caz2z2 and y Henry 8. Young 62/ R 4/ THEIR A TTORNEY Patented May 5, 1936 UNETED STATES RATLWAY TRAFFIC CONTROLLING APPARATUS Ronald A. McCann, Swissvale, and Henry S.

Young, Wilkinsburg, Pa.,

assignors to The Union Switch & Signal Company, Swissvale, Pa, a corporation of Pennsylvania Application November 13, 1934, Serial No. 752,842

9 Claims.

Our invention relates to railway traffic controlling apparatus, and particularly to apparatus for controlling signals or other signaling devices at locations where a dead section of track occurs in an otherwise continuous track circuited territory due, for example, to a multiple track railroad crossing.

At such locations it is customary to provide a stick circuit commonly known as a trap circuit, which circuit is controlled by the track relays in such manner that this circuit will not become restored after it has been operated by a train until the train has passed a predetermined distance beyond the dead section. With trap circuits arranged and controlled in the manner they have heretofore generally been arranged and controlled, if a power interruption occurred which caused the trap circuit to become deenergized, this circuit would usually remain deenergized until the circuit was manually restored to its normally energized condition. One object of our present invention is to provide a trap circuit which will automatically become restored to its normally energized condition following a power interruption.

We will describe one form of apparatus embodying our invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of apparatus embodying our invention.

Referring to the drawing, the reference characters l and l designate the track rails of a stretch of railway track over which trafiic normally moves in the direction indicated by the arrow. These track rails are divided by means of insulated joints 2, into blocks only one of which, CF, is shown in the drawing, and the block CF is further divided by means of insulated joints 2 to form a plurality of track sections CD, DE and EF. Intersecting section D--E is a crossing G here shown for purposes of illustration as a double track railroad crossing. This crossing is insulated from the re.- mainder of section DE by means of additional insulated joints 2, thus forming a dead section a-b within section DE. The rails I and I of section DE on opposite sides of the dead section, however, are connected together by means of suitable conductors 3 and 4.

Connected with the rails of each track section adjacent one end of the section is a source of track circuit current, here shown as the secondary 5 of a transformer designated as a whole by the reference character T with a suitable distinguishing exponent. The primary 6 of each transformer T is constantly connected with the terminals B and X of a, suitable sourc of alternating current not shown in the drawing. Also connected with the rails of each track section at the end opposite the associated transformer T is a track relay designated by the reference character R with a suitable distinguishing exponent.

The track relay R controls a track repeater relay TP, which latter relay is also controlled by a power off relay POR. The circuit for relay TP passes from terminal B of the source through front contact 1 of track relay R front contact 8 of power off reIay'POR, and the windingof relay TP to terminal X ofthe source. It will be apparent, therefore, that relay TP will be energized when and only when track relay R and power off relay POR are both energized.

The power off relay POR is provided with a pickup circuit which is controlled by a stick relay S, and which passes from terminal B of the source through front contact 9 of relay S and the winding of relay POR to terminal X. Relay POR is also provided with .a stick circuit which passes from terminal B of the source through front contact IU of relay POR and the winding of relay POR to terminal -X. It will be apparent, therefore, that when relay POR has once become energized, it will subsequently remain energized by virtue of its stick circuit until a power failure occurs, and that when a power failure does occur,

this relay will subsequently remain deenergized until stick relay S has first become energized and completed the pick-up circuit for this relay.

The stick relay S is provided with two pick-up circuits which are each controlled by track relays R and R and by repeater relay TP, and with a stick circuit which is controlled in part by track relay R The one pick-up circuit for relay S is closed when relays R and TP are both energized and relay R is deenergized, and passes from terminal B of the source through front contact I I-I l of relay TP, wire l2, back contact |3l3 of relay R wire I4, front contact H) of track relay R wire [6, and the winding of relay S to terminal X of the source. The other pick-up circuit for relay S is closed when track relays R and R are both energized and relay'TP is deenergized and passes from terminal B of the source through back contact ll of relay 'IT, wire I1, front contact I3l3 of relay R wire I, front contact l5 of relay R wire 16, and the winding of relay S to terminal X. The stick circuit for relay S is closed when and only when relay R, is energized and relay S is also energized and passes from terminal B of the source through front contact [8 of track relay R wire l9, front contact 20 of relay S, wire 2|, and the winding of relay S to terminal X.

Traffic entering block CF is controlled by a signal C which, as here illustrated, is of the two-position semaphore type capable of indicating proceed or stop according as the signal mechanism is energized or deenergized. It should be distinctly understood, however, that this particular type of signal is not essential to our invention. The signal C is controlled by the track relays R R and R by repeater relay TP, and by stick relay S in such manner that this signal will indicate proceed when and only when these relays are all energized. The circuit for signal C passes from terminal B of thesource through front contact 23 of relay S, wire 24, front contact 25 of relay TP, wire 26, front contact 2! of track relay R wire 28, front contact 29 of track relay R wire 30, front contact 3| of track relay R wire 32, and the operating mechanism of signal C to terminal X.

The operation of the apparatus as a whole is as follows: As shown in the drawing, track sections CD, DE and EF are all unoccupied so that track relays R 1'1. and R. are all energized, and since these track relays are all energized, relays POR, S and TP are all energized, and signal C indicates proceed.

We will now assume that a train traverses the stretch of track shown in the drawing in the direction indicated by the arrow. When the train enters section CD, relay R will become deenergized and will open its front contacts 3| and I. The opening of front contact 3| of relay R will interrupt the circuit for signal C and this signal will therefore move to its stop position, thus preventing a following train from entering block CF. The opening of front contact I of track relay R will deenergize track repeater relay TP, but the deenergization of this relay under these conditions will have no effect on the remainder of the apparatus. When the train enters section DE, track relay R will become deenergized, and will interrupt both pick-up circuits and the stick circuit for relay S, as well as the circuit for signal C Stick relay S will therefore become deenergized, and signal C will remain in its stop position. When the train leaves section CD, relay R will pick up and will complete the pick-up circuit for relay TP, thus causing this latter relay to become reenergized. The energization of relay 'I'P, however, will have no effect on the remainder of the apparatus. As the train moves through section DE, if the length of the train exceeds that of the dead section a-b, relay. R w ill remain continuously deenergized. If, however, the train is shorter than the length of the dead section, relay R. will pick up while the train is passing through the dead section. When relay R picks up under these conditions, stick relay S will remain deenergized because the one pick-up circuit for this relay will then be open at back contact Il-l l of repeater relay TP, the other pick-up circuit for this relay willbe open at back contact l3-l3l of track relay R and the stick circuit for this relay will be open at its own front contact 20. Signal C will therefore remain in its stop position. It follows that even though the train is shorter than the dead section, so that it fails to shunt the track circuit for section DE while it is traversing the dead section, a dangerous condition will not exist. As soon as the train leaves the dead section, relay 1?. will, of course, again become deenergized. When the train enters sections EF, track relay R will become deenergized, thus maintaining the circuit for signal C open while the train is passing through section EF. When the train leaves section DE, relay R will pick up, and when this relay picks up, the pick-up circuit for stick relay S including front contact llll of repeater relay '1? and back contact |3l3 of track relay R will become completed. Stick relay S will therefore pick up and will complete its stick circuit. When the train leaves section E-F, track relay R will pick up and will complete the circuit for signal C thus causing this signal to move to its proceed position. When signal C reaches its proceed position, all parts 1 will then be restored to the positions in which they are shown in the drawing.

We will now assume that a train moving in the direction indicated by the arrow moves into section DE and then backs up past the point C. When the train enters section CD, relay R will become deenergized and will cause signal C to move to its stop position, and relay TP to also become deenergized; and when the train enters section DE, relay R. will become deenergized and will deenergize stick relay S, the operation up to this point being identical with that previously described. When the train backs out of section DE, relay R will again become energized, and since relay R will then be deenergized so that relay TP will also be deenergized, the pick-up circuit for relay S including back contact lI---ll of,

relay TP and front contact l3-I3"- of relay R will become closed, thus causing relay S to pick up and complete its pick-up circuit. When the train backs out of section C-D, relay R will pick up and, when this relay picks up, signal C will again move to its proceed position. All parts will then be restored to their normal positions.

It follows from the foregoing that, when a train enters section DE and causes stick relay S to become deenergized, this relay will subsequently remain deenergized until the'train passes completely into either one of the adjacent sections. It also follows that signal C will not indicate proceed after a train has entered block CF until after the train has passed completely out of one.

end or the other of the block.

We will now assume that the parts are in the positions shown in the drawing and that a power failure occurs so that all relays become simultaneously deenergized and signal C moves to its stop position. Under these conditions, when the power is subsequently restored, track relays R R and R will immediately pick up, and as soon as track relays R and R pick up, the pick-up circuit for stick relay S including back contact lll l of relay TP and front contact l3l3f of track relay R will become completed. Stick relay S will therefore pick up and will complete its own stick circuit, as well as the pick-up circuit for power off relay POR. When relay POR becomes energized, it will complete its stick circuit and the pick-up circuit for relay TP. Relay TP will therefore become energized and, when this relay becomes energized, it will complete the circuit for signal C thus causing this signal to be restored to its proceed position. When the signal reaches its proceed position, all parts will be fore the power failure occurred.

It should be pointed outzthatwhile in describing our invention we have shown the apparatus applied to the control of a signal, the apparatus might equally well be utilized. to control interlocking mechanism of any suitable type which may be utilized in connection with the crossing G.

Although we have herein shown and described only one form of railway traffic controlling apparatus embodying our invention, it is: understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of our invention.

Having thus described our invention, what we claim is:

1.111 combination, astretch of railway track divided into a plurality of successive sections e dead section formed in an intermediate one of said sections, a track circuit for each track section including a source of power and a track relay, a normally energized relay controlled by all of said track relays in such manner that said normally energized relay will become deenergized whenever a train enters said intermediate section and will subsequently remain deenerigzed until the train passes completely into one or the other of the adjacent sections, auxiliary means eifective in the event that all of said relays become deenergized due to a power failure for re-energizing said normally energized relay when the power is restored, and traffic controlling means controlled by said normally energized relay.

2. In combination, a stretch of railway track divided into a plurality of successive sections, a dead section formed in an intermediate one of said sections, a track circuit for each track section including a common source of power and a track relay, a normally energized relay controlled by all of said track relays in such manner that said normally energized relay will become deenergized whenever a train enters said intermediate section and will subsequently remain deenergized until the train passes completely into one or the other of the adjacent sections, auxiliary means effective in the event that said normally energized relay becomes deenergized due to a power failure for re-energizing said normally energized relay when the power is restored, and traffic controlling means controlled by said normally energized relay.

3. In combination, a stretch of railway track divided into first, second, and third successive track sections, a dead section formed in said second section, a source of current, a track circuit for each track section receiving current from said source and including a track relay, a power off relay, a track repeater relay provided with an energizing circuit including a front contact of the track relay for said first section and a front contact of said power ofi relay, a stick relay, a pick-up circuit for said power off relay receiving power from said source and including a front contact of said stick relay, a stick circuit for said power off relay receiving power from said source and including its own front contact; a first pickup circuit for said stick relay including a front contact of said repeater relay, a back contact of the track relay for said third section, and a front contact of the track relay for said second section; a second pick-up circuit for said stick relay including a back contact of said repeater relay and front contacts of the track relays for said second and third sections; a stick circuit for said stick relay including its own front contact and a. front contact of the track relay for said second section; and traflic controlling means controlled by said stick relay,

4. In combination, a stretch of railway track divided into first, second, and third successive track sections which comprise a block, a dead section formed in said second section, a source of current, a track circuit for each track section receiving current from said source and including a track relay, a power ofi relay, a track repeater relay provided with an energizing circuit including a front contact of the track relay for said first section and .a front contact of said power off relay, a stick relay, a pick-upcircuit for said power off relay receiving power from said source and including a front contact of said stick relay, a stick circuit for said power oif relay" receiving power from said source and. including its own front contact; a first pick-up circuit for said stick relay including a front contact of said repeater relay, a back contact of the track relay for said third section, and. a front contact of the track relay for said second section; a second pick-up circuit for said stick relay including a back contact of said repeater relay and front contacts of the track relays for said second and third sections, a stick circuit for said stick relay including its own front contact and a front contact of the track relay for said second section, a signal for governing the entrance of traflic into said block, and a circuit for said signal including a front contact of each of said track relays, a front contact of said track repeater relay, and a front contact of said stick re ay.

5. In combination, a stretch of railway track divided into first, second, and third successive track sections, a dead section formed in said second section, a track circuit for each track section including a track relay, a power off relay, a track repeater relay controlled by said power off relay and by the track relay for said first section, a stick relay controlled by said track repeater relay and by the track relays for said second and third sections, means controlled by said stick relay for controlling said power off relay, and trafiic controlling means controlled by said stick relay.

6, In combination, a stretch of railway track divided into first, second, and third successive track sections, a dead section formed in said second section, a track circuit for each track section including a track relay, a power off relay, a track repeater relay controlled by said power off relay and by the track relay for said first section, a stick relay controlled by said track repeater relay and by the track relays for said second and third sections, means controlled by said stick relay for controlling said power off relay, and a signal for governing trafiic over said stretch controlled by said stick relay.

7. In combination, a stretch of railway track divided into first, second, and third successive track sections, a dead section formed in said second section, a track circuit for each track section including a track relay, a power 01f relay, a track repeater relay controlled by said power off relay and by the track relay for said first section, a stick relay controlled by said track repeater relay and by the track relays for said second and third sections, means controlled by said stick relay for controlling said power ofi relay, and means for governing trafiic over said stretch controlled by said stickrelay and by said track repeater relay.

'said stick relay for controlling said power oil relay, and means for governing trafilc over said stretch controlled by said stick relay, by said track repeater relay, and by all of said track relays.

9. In combination, a stretch of railway track divided into first, second, and third'successive sections," adead section formed in said second section, a track-circuit for eachoi' said sections including a common source of powerand a track relay, a normally. energized relay controlled by all of said track relays in such manner that said normally energized relay will become deenergized whenever a train enters said second section and will subsequently remain deenergized until the .train passes completely into said .first or.said

third section, auxiliary means effective in the 1'10 event that all or said relays become deenergized .due to a power failure for reenergizing said normally energized relay when the power is subsequently restored, and-a signal for governing relays.

RONALD A. McCANN. HENRY S. YOUNG.

trailic over said stretch controlled by all of said 15 

